1. Field of the Invention
The present invention relates to a method for the concentration or enrichment of dusts obtained in a cupola furnace with metals and their oxides, wherein the dusts formed in the cupola furnace are intercepted by means of a filter arrangement.
2. Description of the Invention
Shaft furnaces, in particular cupola furnaces, for smelting cast iron have been known for a long time. The metallic charge is smelted with the addition of energy carriers, crude iron, returned material and scrap being employed in varying quantitative proportions.
Various metals contained in the scrap fraction, such as, for example, zinc, cadmium, lead, etc. vaporize during this smelting process. To prevent air pollution, stringent requirements must be met by the collection of dust from cupola furnace waste gases, so that the resulting gaseous metal particles are no longer allowed to be discharged into the open but must be intercepted in a filter arrangement provided downstream of the cupola furnace. In the past, metallic dusts collected in the filter have been treated in various ways such that they were rendered suitable for dumping and disposal was possible.
It is the object of the present invention economically to recover metallic fractions which collect in a filter arrangement of a cupola furnace, in order to avoid dumping which pollutes the environment and causes costs.